From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965483AbXCPQTO (ORCPT ); Fri, 16 Mar 2007 12:19:14 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965481AbXCPQTN (ORCPT ); Fri, 16 Mar 2007 12:19:13 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:47588 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965483AbXCPQTM (ORCPT ); Fri, 16 Mar 2007 12:19:12 -0400 Date: Fri, 16 Mar 2007 17:18:53 +0100 From: Ingo Molnar To: Paulo Marques Cc: Alexey Dobriyan , akpm@osdl.org, linux-kernel@vger.kernel.org, devel@openvz.org, tglx@linutronix.de, viro@zeniv.linux.org.uk, rusty@rustcorp.com.au Subject: Re: [PATCH RESEND 2/2] Fix some kallsyms_lookup() vs rmmod races Message-ID: <20070316161853.GD9413@elte.hu> References: <20070316114458.GB6817@localhost.sw.ru> <20070316115154.GC30195@elte.hu> <45FAC2CA.80009@grupopie.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <45FAC2CA.80009@grupopie.com> User-Agent: Mutt/1.4.2.2i X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.0.3 -2.0 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org * Paulo Marques wrote: > >looking at the problem from another angle: wouldnt this be something > >that would benefit from freeze_processes()/unfreeze_processes(), and > >hence no locking would be required? > > I also considered this, but it seemed a little too "blunt" to stop > everything (including completely unrelated processes and kernel > threads) just to remove a module. 'just to remove a module' is very, very rare, on the timescale of most kernel ops. Almost no distro does it. Furthermore, because we want to do CPU-hotplug that way, we really want to make freeze_processes()/unfreeze_processes() 'instantaneous' to the human - and it is that already. (if it isnt in some case we can make it so) Ingo